Cardboard box



CARDBOARD BOX 7 3 Filed Feb. 24, 1967 sheets-sheet 1 Fig.1

INVENTOR 5 Jan ni-sfen H kansson Rolf ma nus DI/D'b BY W AWE; P

ATTORNEYs Jan. 2, 1968 J. HAKANSSON ET AL 3,361,325

' I CARDBOARD 30X Filed Feb. 24, 1967' 3 heetsSheet 2 Fig. 3

' INVENTORS Ja n Tor'slzen Hakah $5 on Rolf Magnus Dl'lot ATTORNE Y5 Filed Feb. 24, 1967 Jan.'2, 1968 sso ET AL 3,361,325

CARDBOARD BOX 3. Sheets-Sheet 5 Fig.5

INVENTOR; Jan Torsfien Hakansson Rob Magnw D/loi BY PM JWAQ 1 ATTORNEYS United States Patent Ofiice 3,361,325 Patented Jan. 2, 1968 3,361,325 CARDBOARD BOX Jan Hakansson, Eslov, and Rolf Dilot, Lund, Sweden, assignors to AB Akerlund & Rausing, Lund, Sweden, a Swedish joint-stock company Filed Feb. 24, 1967, Ser. No. 618,390 Claims priority, application Sweden, Mar. 3, 1966, 2,781/ 66 3 Claims. (Cl. 229-33) ABSTRACT OF THE DISCLOSURE A rectangular cardboard box is erected from a blank structure which includes a rectangular bottom panel, four side panels joined to the bottom panel by fold lines, and four additional, corner panels disposed respectively between adacent side panels at the four corners of the bot tom panel and joined to the side panels by fold l'mes. Each corner panel includes a slot extending inwardly from one edge thereof and a fold line extends diagonally from the bottom of the slot to a corner of the bottom panel. During erection of the box, the side panels are folded upwardly to locate them perpendicular to the bottom panel and the corner panels divided in part by the slot are folded upwardly and inwardly to establish a fin which is then folded again so as to lie fiat against a side of the box. The fin has a double thickness in the vicinity of the box corner and a single thickness for the remainder of its length.

The blank may or may not include at lid panel joined along one side to one side panel, the lid panel having side lid panels joined to the other three sides thereof. After erection of the main box structure, and after the latter has been filled with the contents desired, the lid panel is folded to close the box, and the side lid panels are sealed closed to the sides of the box.

A machine is provided for erecting the main box structure, the machine including a rectangular open shaft of the same size as the bottom panel of the box blank, and a rectangular stamp which engages the bottom panel of the blank when brought into registry with the open shaft and pushes the bottom panel down into the shaft. As the bottom panel moves downwardly through the open shaft, the side panels are automatically folded upwardly and the corner panels are also folded so as to project outwardly in the form of fins. As the partially erected box continues its downward movement, the corner fins are folded so as to lie flat against the sides of the box and are pressed against and sealed to the box sides by rolls. A suction cup operating from beneath the shaft is used to remove the erected carton after being discharged from the bottom of the shaft.

The present invention refers to a cardboard box and a machine for erecting the same. The object of the invention is to provide a cardboard box which is economic in respect of the consumption of material, which is easy to stamp and crease, which can be erected mechanically rapidly and easily, and the filling and sealing of which affords no difliculties. Furthermore, after sealing, the cardboard box preferably is to have quite smooth surfaces suitable to decoration. Finally, the cardboard box according to the invention should have a tight bottom construction. To provide such a cardboard box it has also been necessary to invent a new box erecting machine which is specifically adapted to it.

The invention starts from a cardboard box of the kind which includes a bottom panel, four side panels integral with the latter, and at least two and preferably four corner panels each of which is integral with two adjacent side panels and each of which is intended at the erection of the cardboard box to be doubled and folded in towards one of the adjacent side panels.

It is characteristic of the invention that each corner panel is subdivided in part by means of a slot or notch into two part panels such that at the erection of the cardboard box a fin is formed which is doubled nearest the corner and which is folded in towards the box side and, remote from the corner, passes into a single ply.

As mentioned above, the invention also includes a machine for erecting the cardboard box described above. The characteristic features of this machine will appear more closely from the following claims.

The invention will be described in further detail in the following with reference to the accompanying drawings which, by way of example, shows a preferred form of the carboard box according to the invention, on the one hand, and a machine for erecting this box, on the other hand.

FIG. 1 shows a blank of the illustrated preferred form of the cardboard box according to the invention.

FIG. 2 shows the same cardboard box erected but not yet closed.

FIG. 3 shows the same cardboard box completely closed.

FIG. 4 shows a perspective view of the most essential details of the said machine for erecting the cardboard box shown in FIGS. 1-3.

FIGS. 5-7 finally show various detail views of the machine shown in FIG. 4.

The flat blank 1 shown in FIG. 1 consists of a rectangular bottom panel 2, four side panels 3, 4, 5 and 6 integral with this panel 2 and four corner panels subdivided by a notch 7 into two part panels 8 and 9. Further, the blank includes a rectangular lid panel 10 with three side lid panels 11, 12 and 13. Finally, 14 designates creasing lines in the blank which connect the four corners of the bottom panel 2 with the nearest notch 7 and which are intended to control the box erection together with the normal creasing lines 15 confining the bottom and side panels and their extensions 16.

As will be best seen from FIG 2, the corner panels 8, 9 are double at the erection of the cardboard box in such a way that nearest the respective corner they form a doubled fin which at a certain distance passes into a fin consisting of a single layer only, and more particularly of the outer nart of the part panel 9.

FIG. 3 shows how the finished cardboard box presents completely smooth outer surfaces, i.e., surfaces very well adapted to carry decoration. The side lid panels 11, 12 and 13 are preferably fastened to the outsides of the side walls 3, 5 and 6 by means of heat sealing. As an adhesive there may be used either a plastics coating covering the inside and/or outside of the whole cardboard box or such a coating preapplied as spots or lines at convenient places. Alternatively, an ordinary paste may be applied directly in connection with the final sealing. In practice, it has proved convenient to use paste of the socalled hot melt type.

How the cardboard box according to the invention is erected in a convenient manner is best seen from FIGS. 4-7. In these figures, however, for the sake of clearness several details have been broken at the same time as certain details have been omitted altogether. From a supply not shown the flat blank shown in FIG. 1 is fed along a conveyor path 17 of any kind past heating means, not shown either, which heat the surfaces of the corner panels 8, 9 intended for sealing and preferably also the outside of the end walls 5 and 6. When the blank arrives exactly above a shaft 18 it is seized by a stamp 19, part of which is shown in FIG. 6 and which is indicated by dot and dash lines in FIG. 4. The shaft 18 has a cross-sectional form which substantially conforms to the outer cross-sectional form of the cardboard box. At each of the upper corners of the shaft 18 rollers 20 are provided in pairs. When the cardboard box is pressed down into the shaft 18 by the stamp 19, the side walls 3-6 are erected at the same times as the corner panels 8, 9 are doubled and directed straight outwards from the box, as is shown to the left in FIG. 4. Directed in this way the corner panels are caused to pass between the rollers 20 provided in pairs, whereby the preheated inner surfaces of the corner panels 8, 9 are compressed to form a good seal.

Immediately after the position shown in FIG. 4 the stamp 19 operates a pivotally mounted sheet metal member 21 which via a roller and link transmission 22-28 operates a folding and guiding flap 29 which intercepts the doubled corner panel 8, 9 and folds it in towards the end wall of the cardboard box. The fin formed by this panel will thereby run inside the guiding sheet metal member 30 which is fixed to a holder 31 which also carries pressing rollers 32 and 33 the working peripheral surfaces of which project through holes in the guiding sheet metal member 30. The construction is of course such that there is such a holder 31 with a guiding sheet metal member 30 and pressing rollers 32 and 33 at each end of the shaft. This also applies to the remaining details provided in the shaft. The movement of the folding and guiding fiaps 29 also functions to ensure that these flaps do not fold in the side lid panels 12 and 13 in the same way as the corner panels 8, 9, i.e., these side lid panels pass at the opposite side of the flaps 29 as compared with the corner panels.

The function of the pressing rollers 32 and 33 will be best understood from the detail view of FIG. 7. As will be seen from this figure and from FIG. 6 the roller 33 projects farther into the shaft 18 than the roller 32. The reason of this is that the roller 32 is intended to press in the doubled part of the corner panels 8, 9 sealingly, while the roller 33 is adapted to press in the single projection part of the part panel 9 against the box side.

FIG. shows the inside of one box wall of the shaft 18 as seen from the center of the shaft. A jaw of nylon, Teflon or any other material with small coefiicient of friction is shown at 34. This jaw is besides serrated for still further reducing the friction. Thereby the erection of the cardboard box issubstantially facilitated.

When the cardboard box has been forced through the shaft 18 it is seized by the suction cup 35 which strips it from the stamp 19 at the return stroke of the latter. So as to ensure this stripping still further the stamp 19 is provided with an air blowing hole 36 (FIG. 6) to which air is supplied from a source not shown when the stamp is about to turn. Thereby the side wall of the cardboard box is pressed out and engages the bottom edge of the guide sheet metal member 30 serving as a stripping edge.

The suction cup 35 moves the erected cardboard box down to a second conveyor path (not shown). Along this conveyor path there are first provided one or more filling stations for filling the cardboard boxes and thereupon a final sealing station. This final sealing may proceed in such a way that a plastics coating already applied to the cardboard box is heated on the inside of the side lid panels 11-13 and/ or on the outside of the side walls 3-6. In this case one may work either with completely plastics coated cardboard or with adhesive applied as spots or lines.

The invention is of course not limited to example described above only but may be varied within the scope of the following claims.

Thus, for example, the particular details of the machine shown may be varied in many respects relating to both construction and material. The cardboard box shown may of course be manufactured without a lid. In that case the sealing thereof may take place, for example, by completely enclosing it in heat shrinkable plastics.

What is claimed is:

1. A rectangular cardboard box structure erected from a box blank which includes a rectangular bottom panel, four side panels joined to said bottom panel by fold lines and four additional corner panels disposed respectively between adjacent side panels at the four corners of said bottom panel and joined to said side panels by fold lines, each said corner panel being divided in part by a slot extending inwardly from one edge thereof and a fold line extending diagonally from the bottom of the slot to a corner of said bottom panel, each of said side panels being folded upwardly to a position perpendicular to said bottom panel, and each of said corner panels being folded upwardly and inwardly to establish a fin that is folded flatly against and sealed to one of said side panels, each said fin being of double thickness in the vicinity of a box corner and being of single thickness for the remainder of its length.

2. A rectangular cardboard box structure as defined in claim 1 and wherein the box blank includes a rectangular lid panel joined along one side thereof by a fold line to one of said side panels, said lid panel including side lid panels joined by fold lines to the other three sides thereof, said side lid panels being folded over and sealed to corresponding side panels of said box and covering said fins.

3. A rectangular cardboard box structure as defined in claim 1 wherein said corner panels are provided with a heat sealing coating.

References Cited UNITED STATES PATENTS 1,297,636 3/1919 Bachmann 229-31 1,694,126 12/1928 Joslin 22931 3,231,171 1/1966 Weiss 229-33 DAVID M. BOCKENEK, Primary Examiner. 

